UPDATED (to be more precise in the answers I seek)
In your mind, is it:
"A podcast is like radio" ("radio" the medium, not the hardware/technoogy)
"A podcast is like a radio show" (the usage of the medium)
The difference is VERY significant. Please think about it and let me know.
Answers to this question very clearly indicate biases based on usage and understanding of what is, fundamentally, a profoundly simple thing: a media file URI culled out of a "blog entry" and highlighted in some fashion ("enclosures") in a syndication feed...